Creating a Longitudinal Data System: Using Data To Improve Student Achievement - The Data Quality Campaign (DQC) has identified 10 essential elements of a longitudinal education data system to improve student achievement. This report describes these 10 elements and actions states must take to incorporate them into their data systems. Further, the report spells out how the elements help answer key performance questions for policymakers and other interested parties. The 2006 update indicates the number of states that have adopted each of the elements and the change since 2005. For example, 42 states reported having a unique student identifier in place, up from 36 in 2005. And 14 states are able to identify the percentage of high school graduates who take remedial courses once enrolled in college. (Data Quality Campaign, 2006)...